Abstract : Retrofitting convective forced air heating systems with infrared (IR) systems can save as much as 50 percent of the total heating bill. Infrared heating is more efficient for two reasons: it can be directed to heat only occupied space; and it does not heat the air in a space, it only heats people and objects. Infrared heating works best where convective heaters are not practical. Large open bay buildings, such as hangars, workshops, and warehouses, with large volumes of air to be heated and plenty of unoccupied space are good candidates for retrofit. This TechData Sheet will help activity personnel understand infrared radiant heating, and identify opportunities for energy-conserving retrofit projects.